Put on the whole armour of God, that ye may be able to stand against the wiles of the devil. For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places. Wherefore take unto you the whole armour of God, that ye may be able to withstand in the evil day, and having done all, to stand. Stand therefore, having your loins girt about with truth, and having on the breastplate of righteousness; And your feet shod with the preparation of the gospel of peace; Above all, taking the shield of faith, wherewith ye shall be able to quench all the fiery darts of the wicked. And take the helmet of salvation, and the sword of the Spirit, which is the word of God.

-Bible (NewTestament)
Ephesians 6:11^17.

All in the blue unclouded weather Thick-jewelled shone the saddle leather, The helmet and the helmet-feather Burned like one burning flame together, As he rode down to Camelot.

-Tennyson
  Poems,'The Lady of Shalott' (revised1842), pt.3, l.91^5.

She left the web, she left the loom, She made three paces through the room, She saw the water-lily bloom, She saw the helmet and the plume, She looked down to Camelot. Out flew the web and floated wide; The mirror cracked from side to side; 'The curse is come upon me', cried The Lady of Shalott.

-Tennyson
  Poems,'The Lady of Shalott' (revised1842), pt.3, l.109^17.